This document contains some overall description of the various declassified satellite imagery datasets that I’ve been playing around with for the last few months. They were downloaded from https://earthexplorer.usgs.gov/.
First, I’ll briefly re-introduce the three data sources:
Declassified 1 is the product of a blanket declassification in 1995 and purportedly represents all of the images from the following satellite programs:
CORONA: 1960-1972.
ARGON: 1962-64
LANYARD: 1963.
It’s not clear which images come from which satellites systems.
The dataset contains 837088 images. A handful of different camera setups were used during the program:
unique(sat1$`Camera Resolution`)
## [1] "Vertical Medium" "Stereo Medium" "Vertical Low" "Vertical High"
## [5] "Stereo High"
unique(sat1$`Camera Type`)
## [1] "Vertical" "Aft" "Forward" "Cartographic"
It’s not clear how the resolution of these cameras (e.g. “High” & “Low” resolution) compares to the later generations, i.e. KH-7 and KH-9.
Here is the total “footprint” of the images in this dataset (shapefile supplied by USGS):
As you can see, declass1 images cover most of the globe.
Declassified 2 is the product of a 2002 declassification involving the non-comprehensive declassification of imagery from the following programs:
KH-7 (GAMBIT): images taken between 1963 and 1967, the full lifespan of GAMBIT.
KH-9 (HEXAGON): images taken from 1973 to 1980, a subset of the operational period of HEXAGON.
It’s not clear whether all of the images from KH-7 were declassified or whether some were withheld. Only a subset of the KH-9 images were declassified.
The dataset contains 46,699 images.
KH-7 was used for higher-resolution surveillance. KH-9 had both a lower-resolution mapping camera and a higher-resolution surveillance camera, but only the mapping images were declassified in this declassification act:
unique(sat2$`Camera Resolution`)
## [1] "2 to 4 feet" "20 to 30 feet"
unique(sat2$`Camera Type`)
## [1] "KH-7 High Resolution Surveillance" "KH-9 Lower Resolution Mapping"
Here is the total “footprint” of the images in this dataset (shapefile supplied by USGS):
As you can see, declass1 images cover most of the globe.
Declassified 3 is the product of a 2011 declassification involving the non-comprehensive declassification of imagery from KH-9 (HEXAGON), which ran from 1971 to 1984. This includes images from the high-resolution surveillance camera, but the website says that “almost all of the imagery from these cameras were declassified in 2011” implying that some images remain classified.
The dataset contains 531,321 images. Note that the website says that “The process to ingest and generate browse imagery for Declass-3 is ongoing,” and suggests that the HEXAGON program generated over 670,000 scenes, indicating that the dataset which we have access to is missing a substantial chunk of the images from HEXAGON.
Both the terrain mapping and surveillance imagery were included in this declassification:
unique(sat3$`Camera Resolution`)
## [1] "2 to 4 feet" "20 to 30 feet"
unique(sat3$`Camera Type`)
## [1] "High Resolution Surveillance Camera - Forward"
## [2] "High Resolution Surveillance Camera - Aft"
## [3] "Lower Resolution Terrain Mapping Camera"
Here is the total “footprint” of the images in this dataset (shapefile supplied by USGS):